The Police Federation has warned it may take two years to get enough armed officers

“We have seen what happened in Nice when the only way of stopping that truck was with armed officers.

“The reality is that if the same thing happened here then there would not be enough cover to stop it in its tracks.

“It is a serious concern.’’

Recruitment problems have been blamed on lengthy legal proceedings and arrests of officers who discharge firearms in life and death situations on duty.

Mark Williams, chief executive of the Police Firearms Officers Association, which is assisting forces to help recruit, said : “The sticking point seems to be the way in which discharges of firearms are investigated.